Acesulfam K is a non-sucrose sweetener developed by Hoechst Corporation. According to its manufacturer it is 300-350 times sweet as sucrose. Because of its potential use as a sucrose substitute by individual and industrial consumers, its cariogenic potential was investigated. The experiment consisted of three groups of rats (10/group) which were fed one of the following diets: Group 1 - NIH Diet 2000 (56% sucrose); Group 2 - NIH Diet 2114 (56% raw corn starch) plus 5% Acesulfam K; Group 3 - NIH Diet 2114 (56% raw corn starch). The experiment was performed using a Konig-Hofer programmable feeding machine which delivered 17 meals/17 hour period of the assigned diets. An additional 6 meals of diet 2114 was provided all three groups as a supplement. All animals were initially infected with S. mutans 6715. Oral infection levels were determined twice weekly. After 56 experimental days the rats were sacrificed. Smooth surface caries scoring reveals a score of near zero for the Acesulfam K group as compared to approximately 14 for the 56% sucrose group and approximately 6 for the 56% raw corn starch group.